1. Field of the Invention
The present invention relates to connected body comprising a terminal and a belt-like conductor laminate, or conductor (which is equivalent to the belt-like conductor laminate when used in the disclosure) and to a method for connecting a terminal to a belt-like conductor laminate.
2. Description of the Prior Art
FIG. 5 shows a connected body comprising a terminal 1 for an electric part such as a capacitor or battery and a belt-like conductor laminate 2 formed by piling up a plurality of thin belt-like conductors as an example of a connected body comprising a terminal 1 and a belt-like conductor laminate 2 of the prior art. Before the terminal 1 is connected to the belt-like conductor laminate 2, the terminal 1 is integrated with the cap 9 of an electric part by insert molding. That is, the terminal 1 is made from a metal material having small electric resistance and has a thin stud 1b projecting from the surface of a base 1a and a thin external electrode 1c coaxial to the stud 1b and projecting from the rear surface of the base 1a. Insert molding is for obtaining a molded piece comprising the base 1a of the terminal 1 integrated with the molded cap 9 by placing the above terminal 1 in a cap mold as an insert member, charging a synthetic resin as a material for molding the cap 9 into a molding space formed in the inside of the cap mold containing the terminal 1 to mold a molded piece consisting of the terminal 1 and the cap 9 and releasing the molded piece from the cap mold. Before the terminal 1 is connected to the belt-like conductor laminate 2, the belt-like conductor laminate 2 has a through hole 2a into which the stud 1b can be inserted in a portion specified as a connection portion with the terminal 1. The connected body is formed by caulking the above terminal 1 to the belt-like conductor laminate 2. To this end, the stud 1b of the terminal 1 is first inserted into the through hole 2a of the belt-like conductor laminate 2 so that the terminal 1 is mated with the belt-like conductor laminate 2 by the stud 1b and the through hole 2a. Thereafter, a pressing member such as a washer is fitted onto a portion projecting from the belt-like conductor laminate 2 of the stud 1b. In this state, a portion projecting from the pressing member 10 of the stud 1b is crushed to caulk the terminal 1 to the belt-like conductor laminate 2.
In the connected body comprising the terminal 1 and the belt-like conductor laminate 2 formed by caulking and the method for connecting the terminal 1 to the charted body 2 of the prior art, it is possible that electric conductivity is insufficient though mechanical strength is relatively high. This is because the mating portions of the terminal 1 and the belt-like conductor laminate 2 are merely strongly contacted to each other by caulking by crushing the stud 1b. When the contact surfaces of the terminal 1 and the belt-like conductor laminate 2 are observed microscopically, there are a large number of extremely small spaces between the contact surfaces.
It is therefore an object of the present invention to provide a connected body comprising a terminal and a belt-like conductor laminate and having high mechanical and electric reliabilities and a method for connecting the terminal to the belt-like conductor laminate.
According to a first aspect of the present invention, there is provided a connected body in which mating portions of a belt-like conductor laminate mated with a thin stud projecting from the base of a terminal and the base are joined together with ultrasonic vibration, and a crushed portion formed by caulking a portion projecting from the belt-like conductor laminate of the stud supports the belt-like conductor laminate with the base.
According to a second aspect of the present invention, there is provided a connected body in which mating portions of a belt-like conductor laminate mated with a thin stud projecting from the base of a terminal and the base are supported by a crushed portion formed by caulking a portion projecting from the belt-like conductor laminate of the stud and the base, and part of the belt-like conductor laminate outside the crushed portion is folded down and joined to the top surface of the crushed portion with ultrasonic vibration.
According to a third aspect of the present invention, there is provided a connection method which comprises the steps of mating a thin stud projecting from the base of a terminal with a belt-like conductor laminate, giving ultrasonic vibration to the outside of at least one of the base of the terminal and the belt-like conductor laminate to join the mating portions of the base and the belt-like conductor laminate, and crushing a portion projecting from the belt-like conductor laminate of the stud to caulk the terminal to the belt-like conductor laminate.
According to a fourth aspect of the present invention, there is provided a connection method which comprises the steps of mating a thin stud projecting from the base of a terminal with a belt-like conductor laminate, crushing a portion projecting from the belt-like conductor laminate of the stud to caulk the terminal to the belt-like conductor laminate, folding down one side of the belt-like conductor laminate with the stud as a boundary between it and the other side, placing it upon the crushed portion of the stud, and giving ultrasonic vibration to the outside of at least one of the base of the terminal and the belt-like conductor laminate to join the mating portions of the crushed portion of the stud and the belt-like conductor laminate.
According to a fifth aspect of the present invention, there is provided a connection method in which ultrasonic vibration is given to the outside of the belt-like conductor laminate.
According to a seventh aspect of the present invention, there is provided a connection method in which a through hole for the stud is formed in the belt-like conductor laminate so that the stud is mated with the belt-like conductor laminate by the through hole.
According to a seventh aspect of the present invention, there is provided a connection method in which after joining with ultrasonic vibration, a pressing member is fitted onto the portion projecting from the belt-like conductor laminate of the stud and a portion projecting from the pressing member of the stud is crushed to caulk the terminal to the belt-like conductor laminate.
The above and other objects, features and advantages of the invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.